Complete response to trastuzumab and chemotherapy in recurrent urothelial bladder carcinoma with HER2 gene amplification: A case report.

BACKGROUND: Targeted treatments may greatly affect the natural history of urothelial carcinoma based on their pharmacokinetics. A phase II trial has explored the combination of cytotoxic chemotherapy with the anti-HER-2 monoclonal antibody trastuzumab in selected patients with metastatic bladder cancer, but it failed. CASE
SUMMARY: Here, we report a case of recurrent urothelial bladder carcinoma (UBC) in a patient who has undergone three operations, and further illuminate its diagnosis and treatment. The diagnosis of UBC was rendered according to the pathological indices. Next-generation sequencing on formalin fixed paraffin-embedded (FFPE) tissue was also performed and suggested HER2 gene amplification in the FFPE tissue. Based on HER2 gene amplification in FFPE, the patient was treated with chemotherapy in combination with trastuzumab after his third surgery. Fortunately, the patient got a clinically complete remission to trastuzumab for 34 mo.
CONCLUSION: There is not enough clinical evidence for incorporating trastuzumab in routine treatment of UBC. This case hinted that recurrent UBC patients with HER2 gene amplification may benefit from targeted trastuzumab. Further studies are needed to further investigate the status of HER2 gene and better determine trastuzumab in the management of UBC. ©The Author(s) 2020. Published by Baishideng Publishing Group Inc. All rights reserved.